改进：显示更新下载进度并就地保存

lite/main.py

@@ -6,7 +6,7 @@ from pathlib import Path
 from PyQt5.QtWidgets import (
     QApplication, QWidget, QLabel, QPushButton,
     QVBoxLayout, QHBoxLayout, QFrame, QMessageBox, QTextEdit,
-    QCheckBox, QMenu, QDialog,
+    QCheckBox, QMenu, QDialog, QProgressDialog,
 )
 from PyQt5.QtCore import Qt, QTimer, pyqtSignal
 from PyQt5.QtGui import QFont, QIcon, QPixmap, QImage, QColor
@@ -1652,6 +1652,7 @@ class MainWindow(QWidget):
     _op_done = pyqtSignal(str, bool)
     _update_done = pyqtSignal()
     _update_download_done = pyqtSignal(bool, str)
+    _update_download_progress = pyqtSignal(int, int, int)
 
     _status_ready = pyqtSignal(object)
     _node_switched = pyqtSignal()   # 启动校验时代替用户切换了节点（刷新标题栏）
@@ -1665,6 +1666,7 @@ class MainWindow(QWidget):
         self._start_in_progress = False
         self._proxy_state_lock = threading.RLock()
         self._status_busy = False      # 防止状态轮询线程堆叠
+        self._update_progress_dialog = None
         # 把全局 log() 函数接到 GUI 日志区
         global _log_func
         _log_func = self.log_signal.emit
@@ -1672,6 +1674,7 @@ class MainWindow(QWidget):
         self._op_done.connect(self._after_op)
         self._update_done.connect(self._on_update_done)
         self._update_download_done.connect(self._on_update_download_done)
+        self._update_download_progress.connect(self._on_update_download_progress)
         self._status_ready.connect(self._apply_status)
         self._node_switched.connect(self._on_node_switched)
 
@@ -2338,8 +2341,35 @@ class MainWindow(QWidget):
                 QMessageBox.Yes,
             )
             if reply == QMessageBox.Yes:
+                self._show_update_download_progress()
                 threading.Thread(target=self._download_update, daemon=True).start()
 
+    def _show_update_download_progress(self):
+        """在 GUI 线程创建下载进度窗口；网络线程只通过 signal 回传状态。"""
+        dialog = QProgressDialog("正在准备下载更新…", None, 0, 100, self)
+        dialog.setWindowTitle("正在下载更新")
+        dialog.setWindowModality(Qt.WindowModal)
+        dialog.setMinimumDuration(0)
+        dialog.setAutoClose(False)
+        dialog.setAutoReset(False)
+        dialog.setValue(0)
+        dialog.show()
+        self._update_progress_dialog = dialog
+
+    def _on_update_download_progress(self, percent, downloaded, total):
+        """把后台下载进度渲染到进度窗口。"""
+        dialog = self._update_progress_dialog
+        if dialog is None:
+            return
+        if total > 0:
+            dialog.setRange(0, 100)
+            dialog.setValue(max(0, min(100, percent)))
+            dialog.setLabelText(
+                f"正在下载更新… {percent}%（{_fmt_bytes(downloaded)} / {_fmt_bytes(total)}）")
+        else:
+            dialog.setRange(0, 0)
+            dialog.setLabelText(f"正在下载更新… 已下载 {_fmt_bytes(downloaded)}")
+
     def _download_update(self):
         """后台下载新版本 EXE 到 EXE 所在目录。
 
@@ -2357,58 +2387,98 @@ class MainWindow(QWidget):
 
             # 对 URL 进行安全编码，兼容空格或已编码空格
             url = urllib.parse.quote(url, safe=':/?#[]@!$&\'()*+,;=%')
-            save_path = PERSIST_DIR / f"Royirin Rosmontis Private Proxy {self._latest_version}.exe"
+            # 冻结程序必须放到当前 EXE 的目录，便于用户关闭旧版后就地替换；
+            # 源码调试则仍写入源码目录，避免误把测试文件写到 Python 安装目录。
+            if getattr(sys, 'frozen', False) or "__compiled__" in globals():
+                download_dir = Path(sys.executable).resolve().parent
+            else:
+                download_dir = PERSIST_DIR
+            save_path = download_dir / f"Royirin Rosmontis Private Proxy {self._latest_version}.exe"
+            part_path = save_path.with_suffix(save_path.suffix + ".part")
             log(f"正在下载新版本: {url}")
             log(f"保存到: {save_path}")
 
-            def fetch(target):
-                # 同更新检查：按「使用代理更新」设置选择隧道或直连
-                if _update_via_proxy():
+            use_proxy = _update_via_proxy()
+            started_here = _ensure_forwarder() if use_proxy else False
+            try:
+                if use_proxy:
                     opener = urllib.request.build_opener(urllib.request.ProxyHandler(
                         {"http": f"{PROXY_HOST}:{PROXY_PORT}",
                          "https": f"{PROXY_HOST}:{PROXY_PORT}"}))
                 else:
                     opener = _pac_no_proxy_opener()
-                with opener.open(urllib.request.Request(target), timeout=120) as resp:
-                    return resp.read()
 
-            started_here = _ensure_forwarder() if _update_via_proxy() else False
+                if part_path.exists():
+                    part_path.unlink()
+                downloaded = 0
+                hasher = hashlib.sha256()
+                last_percent = -1
+                with opener.open(urllib.request.Request(url), timeout=120) as resp, part_path.open("wb") as fp:
                     try:
-                data = fetch(url)
+                        response_size = int(resp.headers.get("Content-Length") or 0)
+                    except (TypeError, ValueError):
+                        response_size = 0
+                    total = self._asset_size or response_size
+                    self._update_download_progress.emit(0, 0, total)
+                    log(f"更新下载进度: 0%（0 / {_fmt_bytes(total)}）" if total else "更新下载进度: 已开始")
+                    while True:
+                        chunk = resp.read(256 * 1024)
+                        if not chunk:
+                            break
+                        fp.write(chunk)
+                        hasher.update(chunk)
+                        downloaded += len(chunk)
+                        if total:
+                            percent = min(100, downloaded * 100 // total)
+                            if percent != last_percent:
+                                last_percent = percent
+                                log(f"更新下载进度: {percent}%（{_fmt_bytes(downloaded)} / {_fmt_bytes(total)}）")
+                                self._update_download_progress.emit(percent, downloaded, total)
+
                 checksum_text = ""
                 if self._checksum_url:
-                    checksum_text = fetch(self._checksum_url).decode("ascii", "replace")
+                    checksum_url = urllib.parse.quote(
+                        self._checksum_url, safe=':/?#[]@!$&\'()*+,;=%')
+                    with opener.open(urllib.request.Request(checksum_url), timeout=120) as resp:
+                        checksum_text = resp.read().decode("ascii", "replace")
             finally:
                 _release_forwarder(started_here)
 
-            if len(data) < 1024:
-                self._update_download_done.emit(False, "下载文件过小，可能不是有效的 EXE")
-                return
-            if self._asset_size and len(data) != self._asset_size:
-                self._update_download_done.emit(
-                    False, f"下载不完整：实际 {len(data)} 字节，应为 {self._asset_size} 字节")
-                return
+            if downloaded < 1024:
+                raise RuntimeError("下载文件过小，可能不是有效的 EXE")
+            if self._asset_size and downloaded != self._asset_size:
+                raise RuntimeError(
+                    f"下载不完整：实际 {downloaded} 字节，应为 {self._asset_size} 字节")
             if checksum_text:
                 want = checksum_text.strip().split()[0].lower()
-                got = hashlib.sha256(data).hexdigest()
+                got = hasher.hexdigest()
                 if len(want) != 64 or want != got:
-                    self._update_download_done.emit(False, "更新包校验失败（SHA-256 不匹配），已放弃")
-                    return
+                    raise RuntimeError("更新包校验失败（SHA-256 不匹配），已放弃")
                 log("更新包 SHA-256 校验通过")
 
-            save_path.write_bytes(data)
+            part_path.replace(save_path)
             log(f"新版本已下载: {save_path}")
             self._update_download_done.emit(True, str(save_path))
         except Exception as e:
+            try:
+                if 'part_path' in locals():
+                    part_path.unlink(missing_ok=True)
+            except Exception:
+                pass
             log(f"下载更新失败: {e}")
             self._update_download_done.emit(False, str(e))
 
     def _on_update_download_done(self, success, message):
         """下载完成后提示用户手动替换 EXE。"""
+        dialog = self._update_progress_dialog
+        self._update_progress_dialog = None
+        if dialog is not None:
+            dialog.close()
+            dialog.deleteLater()
         if success:
             QMessageBox.information(
                 self, "下载完成",
-                f"新版本已下载到:\n{message}\n\n请关闭本程序后，用该文件替换当前运行的程序，然后重新启动。"
+                f"新版本已下载到当前程序所在文件夹:\n{message}\n\n请关闭本程序后，用该文件替换当前运行的程序，然后重新启动。"
             )
         else:
             QMessageBox.warning(self, "下载失败", f"无法下载新版本:\n{message}")